Heat transfer systems and methods

ABSTRACT

A heat transfer enclosure for receiving articles to be processed or stored under conditions of reduced temperature, comprising one or more members of thermally conductive material having a thermal conductivity of at least 10 Wm−1 K−1, the one or more members having a contact surface for contacting articles located in the enclosure and including projections extending generally away from the surface; wherein in use heat is conducted between an article contacting the contact surface with an upper surface of the article and a heat exchange fluid in the heat transfer enclosure via an article—contact surface—projections—heat exchange fluid heat transfer path.

FIELD OF THE INVENTION

This invention relates to heat transfer systems and methods, particularly cooling and heating enclosures such as freezers, chillers, ovens, etc. for cooling or heating articles.

BACKGROUND OF THE INVENTION

Cooling or heating of articles is widely used in a variety of contexts, such as in food preparation and storage, with cooling (chilling, e.g. to a temperature of about 5° C., or freezing, e.g. to a temperature of below about −18° C.) being in widespread commercial use is the processing of foodstuffs and food products for storage and distribution. In a typical refrigeration process (for chilling or freezing) an article is exposed (directly or indirectly) to the effects of a refrigerant fluid (e.g. ammonia, a hydrocholoro-fluorocarbon, etc.) at a lower temperature than that of the article, resulting in transfer of heat from the article to the refrigerant and reduction in temperature of the article. The refrigerant is commonly circulated in a closed system through an evaporator, compressor, condenser and expansion valve for cyclical cooling and heating. The article may be exposed to the refrigerant fluid directly (e.g. as in cryogenic freezing) or (more commonly) indirectly, e.g. via an intervening fluid, typically air that is preferably conveyed past the article, e.g. by use of fans, as in a blast freezer, tunnel freezer, belt freezer, etc., or via an intervening plate, as in a plate freezer. Efficiency of the cooling process depends on a number of factors including the rate of removal of heat from the article. Similar considerations apply in heating processes where articles are typically exposed to a heat exchange fluid, typically in the form of air or steam, at a higher temperature than the articles.

The recessed wisdom is that it is preferable for the lower temperature heat exchange fluid (refrigerant fluid or intervening fluid) to contact as much of the surface of the article as possible for efficient heat transfer and hence efficient chilling. For this reason, articles are commonly located on openwork or wire mesh shelves or supports or on corrugated shelves or supports in chillers and freezers.

However, the present invention is based on a realisation that this view is incomplete, and that there is scope for increasing heat transfer efficiency by use of members in contact with the articles.

SUMMARY OF THE INVENTION

The invention is set out in the independent claims. Preferred embodiments of the invention are set out in the dependent claims.

We describe a heat transfer enclosure for receiving articles to be processed or stored under conditions of reduced or elevated temperature, comprising one or more members of thermally conductive material having a contact surface for contacting articles located in the enclosure and including projections extending generally away from said surface.

In use of the enclosure, a heat exchange fluid (refrigerant fluid or intervening fluid e.g. air in the case of cooling, and typically air or steam in the case of heating) contacts the projections, preferably being conveyed through the enclosure past the projections, e.g. by use of a fan, with the fluid being at a lower temperature than the article for cooling or at a higher temperature for heating, resulting in heat exchange and hence cooling or heating of the article in contact with the contact surface of the member.

In embodiments, the heat transfer path goes (in use) from the article to the contact surface to the projections to the heat exchange fluid (which may be an intervening fluid, as described below).

In some embodiments, the projections may extend generally away from the obverse of the contact surface of the member(s) for contacting articles. In other embodiments, the projections may extend generally away from a (or more) side surface(s) of the member(s), whereby a said member may contact the article with an upper surface or a lower surface of the member. In other embodiments, the projections may extend generally away from multiple surfaces of the member(s), for example the obverse of the above-specified contact surface and one or more side surfaces of the member(s).

The projections of the member function to increase the surface area of the member, thus increasing the surface area of the fluid-solid interface. The member and projections can be considered as effectively increasing the effective surface area of an article in contact with the contact surface and thus increasing the effective surface area of the article in contact with, and heat exchange potential with, the heat exchange fluid.

The equation for conductive heat transfer across a barrier is:

Q=U.A.ΔT

where

-   -   Q is the heat transfer rate (in Js⁻¹)     -   U is the thermal conductivity of the barrier (in Jm⁻²s⁻¹°C⁻¹)     -   A is the surface area of the barrier (in m²)     -   ΔT is the temperature differential across the barrier (in °C)

The mathematical implication is that by increasing the surface area, the heat transfer is also increased, hence the projections, by increasing the surface area of the fluid-solid interface, increase the heat transfer, resulting in more efficient cooling or heating of the article.

It is to be noted that in embodiments, the heat exchange fluid may be a confined refrigerant fluid, an unconfined refrigerant fluid, a confined intervening fluid or an unconfined intervening fluid.

Generally, a refrigerant fluid may be defined as a fluid whose role in cooling or heating involves a change of phase from liquid to gas (in cooling, as in e.g. an evaporator) and gas to liquid (in heating, as in e.g. a condenser).

An intervening fluid may be defined as a fluid whose role in cooling or heating involves no change of phase.

A confined fluid may be defined as a fluid which may be, e.g. in pipes, compressors, etc., and is not intended to come into direct contact with the article or product to be cooled or heated, and may therefore be at a non-ambient pressure—the pressure throughout the system may vary such that if the system may contain some parts above and some parts below ambient pressure, then the pressure of the confined fluid may be within the transition at a point which may be very small where the pressure may cross the pressure equivalent to ambient. However, this transition may be small and may not be exploited to allow a lapse in confinement of the fluid. Generally, a confined fluid may be conserved within the apparatus and may be used repeatedly.

An unconfined fluid may be defined as a fluid outside, e.g. pipes, compressors, etc., and may be at approximately ambient pressure. The unconfined fluid may come into direct contact with the article or product to be heated or cooled. An unconfined fluid may not be conserved within the apparatus, and may be supplied or lost with each use.

In embodiments, a heat transfer enclosure which may use an unconfined fluid may be an enclosure wherein the product or article may be heated or cooled by exposure to, and heat exchange with, an unconfined fluid. The unconfined fluid may be a refrigerant fluid or an intervening fluid with which the product or article may be in contact either directly or indirectly via, for example support structures like shelves or pallet separators, etc.

Therefore, in embodiments of the present invention, the heat transfer path may be established from the product/article to solid structures to projections that dissipate heat from the structures to the unconfined intervening fluid. Generally, in the prior art, the heat transfer is established from the product directly to an unconfined fluid, or from the product to solid structures to the unconfined intervening fluid.

The unconfined intervening fluid may, in embodiments, dump its heat to an evaporator containing a confined refrigerant.

It is noted that solid structures may provide supporting surfaces and may include projections such that the solid structures may be in contact with both the product/article and the intervening fluid. “Solid structures” may not incorporate any surfaces which may be in direct contact with a confined refrigerant fluid, as for example in a “plate freezer”.

In that context, these phrases may follow from the definitions above:

A confined refrigerant fluid may be defined as a confined fluid and also a refrigerant fluid, which may exist in different parts of the system in different phases (liquid and gas).

An unconfined refrigerant fluid (a.k.a. a cryogenic fluid) may essentially be defined as an unconfined refrigerant, e.g. but not limited to liquid nitrogen, dry ice, other evaporative spray coolants, water ice, etc., which may be directly applied to the product/article. Such a material may undergo a one-directional phase change and may then be lost, evaporated, drained away, or disposed of.

An unconfined intervening fluid may be defined as any fluid, for example air in a blast freezer, which is not a refrigerant fluid (in the sense that it remains in the same phase, i.e. if a gas it stays gaseous) that may provide for convection of heat to or away from the product/article.

A confined intervening fluid, like glycol, may be defined as a fluid which is not a refrigerant fluid (in the sense that it remains in the same phase, i.e. if a liquid, it stays a liquid) and may provide for transport of heat within the mechanism of the cooling machinery.

Embodiments of the present invention provide improvements in the heat exchange between product/article and unconfined fluids, such as an unconfined intervening fluid or an unconfined refrigerant fluid.

Examples for a confined refrigerant fluid may be, e.g. freon, ammonia and CO₂.

Examples for an unconfined refrigerant fluid, may be, e.g. liquid nitrogen, dry ice, liquid CO₂, or (e.g. for heating) steam or hot air.

Examples of a confined intervening fluid may be, e.g. glycol, water or brine (in, e.g. a pipe).

Examples of an unconfined intervening fluid may be, e.g. air in a blast freezer of oven, or brine (in, e.g. a tank).

We further note that references to an enclosure are not necessarily limited to closed system, i.e. systems into or out of which no fluid may enter or exit.

The member functions as a heat transfer component and so preferably comprises material having good heat transfer properties, i.e. high thermal conductivity. The term “thermally conductive material” is used to mean material having a thermal conductivity of at least 10 Wm⁻¹K⁻¹, preferably at least 50 Wm⁻¹K⁻¹, more preferably at least 100 Wm⁻¹K⁻¹. The member is preferably made of metal, e.g. steel, aluminium, copper, brass, etc. and mixtures thereof, all of which have thermal conductivities in excess of 100 Wm⁻¹K⁻¹.

Generally, it is appropriate for the projections to extend from the member in a direction in the opposite direction from the article, extending from a surface of the member opposed to the contact surface.

The projections are typically in the form of a plurality of ribs fin plates, columns, etc. extending transversely e.g. at 90° to said contact surface. The ribs, fins, plates or columns may be spaced at regular or irregular intervals, e.g. being in the form of an array of a plurality of parallel, spaced ribs and may be of straight, curved (e.g. corrugated) form etc. As a further possibility, the projections may comprise an array of columns extending transversely, e.g. at 90°, to the contact surface, linked by an array of sheets, ribs or fins of thermally conductive material extending transversely, e.g. at 90°, to the columns, typically extending parallel to the contact surface, with the sheets, ribs or fins constituting part of the projections and functioning to increase the surface area thereof. Another possibility is for the projections to be in the form of an array of plates formed by perforating and deforming a series of regions in a sheet that comprises the contact surface, forming tangs extending away from the contact surface.

The projections may be perforated to increase the surface area thereof. The surface of the projections may be provided with disruptions such as concavities (such as dimples on a golf ball) to break up the boundary layer of heat exchange fluid, and so enhance heat transfer.

The positioning and dimensions of the projections, such as the length, width, spacing etc. may be designed to suit particular intended uses thereof, ideally being optimised for particular intended applications. For example, for general cooling purposes it is convenient to use projections in the form of an array of a plurality of fins or ribs, e.g. in parallel arrangement extending at 90° to the contact surface, with a rib length of about 25 mm, a rib width of about 0.3 mm and rib spacing in the range 2 to 8 mm.

The projections may be integral with and made of the same material as said contact surface, although it is possible for different parts of the member to be made of different thermally conductive materials. As a further possibility, the member may comprise two or more components that come into engagement in use and constitute the member.

The contact surface of the member is designed directly to contact articles located in the heat exchange enclosure, typically contacting a receptacle for food products or contacting the underside of the product itself. The contact surface is preferably a planar surface or substantially planar surface. The contact surface may comprise a single continuous surface (e.g. a planar sheet) or may be constituted by a series of aligned surfaces, possibly contiguous or spaced apart, e.g. constituted by peaks of a corrugated sheet. In one embodiment the member may comprise a planar sheet deformed along a series of parallel lines to produce a zig-zag configuration having an array of aligned planar surfaces constituting the contact surface, a parallel array of aligned planar surfaces constituting an opposed surface, the two surfaces being separated by a series of inclined surfaces constituting projections. The inclined surfaces are preferably inclined at an acute angle with respect to the aligned planar surfaces. The acute angle of inclination may be such that the aligned planar surfaces of the contact surface are closely spaced or contiguous.

It may be useful for the contact surface to have a degree of surface roughness, to reduce the likelihood of articles sticking thereto.

The member may also perform a support function for articles, e.g. comprising a horizontally extending planar contact surface in the form of a shelf or tray on which articles may be placed to contact the underside of the article, i.e. to allow the contact surface of the member to contact the underside of the article. In this case, the member should be capable of bearing intended loads, and is desirably rigid or substantially rigid, at least under intended conditions of use, with the member constituting a structural element. The member may be fixed, possibly removably, with respect to the enclosure or a component thereof.

The member may alternatively be intended to be used with the contact surface in contact with an upper surface of the article. In this case, the member may be of similar construction to that discussed above, to be used in inverted configuration, without the need for load-bearing or rigid properties.

Alternatively, the member may comprise a generally vertically extending contact surface intended to contact a vertically extending side surface of articles, e.g. containers, e.g. being in the form of a vertically extending spacer. Such a spacer conveniently has two parallel vertically extending contact surfaces, for contacting adjacent goods in the enclosure, with projections extending (fully or partially) between the contact surfaces for heat exchange.

As a further possibility, the member may comprise a horizontal spacer having parallel, spaced-apart horizontally extending contact surfaces, to be placed in an interleaving configuration between articles, e.g. containers, stacked on top of each other, with projections extending (fully or partially) between the contact surfaces. These should be suitably load-bearing. Other configurations can be envisaged.

The member may comprise a planar sheet, the upper face of which constitutes the contact surface, with an array of rectangular portions each perforated along three sides thereof (typically including the two major sides) to form a rectangular tang that is deformed out of the plane of the sheet to extend transversely from the sheet e.g. at 90° in a direction away from the contact surface to constitute an array of projections. A further planar sheet may be secured with respect to the free ends of the projections (directly, or via deformed end portions of the projections extending parallel to the contact surface and constituting “feet”, or via projections of an inverted mirror image member) to form a spacer.

The member may further comprise one or more walls extending from the contact surface, in the direction opposed to the projections, for surrounding parts of the article. The walls may be of thermally conductive material or insulating material, e.g. plastics. The walls may effectively form a container for the article. Thus, for example, the member may comprise a shelf or spacer as discussed above with walls extending from the contact surface to form side walls of a rectangular container within which an article may be received.

The member may further constitute a plate of a plate freezer.

To enhance heat transfer, it may be beneficial to urge the article and contact surface into engagement (increasing the contact area of the article and surface), e.g. by applying an appropriately directed force, e.g. by applying a downwards force to the top of an article located on the contact surface. A depressor arrangement may be provided for this purpose, e.g. based on those known in plate freezers. The depressor arrangement conveniently comprises a depressor member having a contact surface for contacting a surface of the article, preferably being designed, to conform to, and maximise contact with, articles with which the enclosure is intended for use, e.g. having a planar surface for contact with articles in the form of boxes, and desirably having formations extending from an opposed surface of the depressor member for contact, in use, with heat exchange fluid, with the depressor member being made of thermally conductive material to further enhance heat transfer.

In a further preferred embodiment of the enclosure, a first said member is inverted compared to an orientation of a second said member, wherein said second member is configured to engage with an article surface opposite to the surface of the article with which said first member engages, and wherein in use said first and/or second member applies a force to urge said article and said contact surfaces of said first and second members, respectively, into engagement. This may be advantageous as the heat transfer may be further enhanced between the article and the heat exchange fluid via the contact surfaces of the members and the respective projections, as multiple members comprising projections may be used, while urging the article and the contact surfaces of the respective members into engagement.

The member may be fixed in position in the enclosure, e.g. in the form of a shelf. Optional fixing means may be provided in the enclosure. The shelf may possibly be adjustable within the enclosure. As a further possibility, the member may move within the enclosure in use thereof, e.g. in the form of moving shelves or trays as are known in the art, to be passed in use through different temperature zones of the enclosure, possibly on different levels.

The enclosure may be, for example, a building or container (e.g. free-standing or part of a vehicle), a room in a building, a compartment or cabinet in a room or container etc. for either cooling or heating purposes. Suitable enclosures are well known in the art. In the case of cooling this includes blast freezers, tunnel freezers, belt freezers, spiral freezers, helix freezers, etc. for use in batch, semi-batch or continuous mode.

The articles are usually discrete, movable items, not being part of a larger fixed structure, and typically comprise food products or foodstuffs, possibly in a receptacle such as a rectangular box or other packaging. For industrial cooling purposes, articles are commonly packaged in containers 600 mm×400 mm×150 mm.

References to reduced temperature mean temperature below ambient. Typically for refrigeration purposes this is a temperature below about 5° C. and for freezing purposes a temperature below about −18° C. or below about −24° C. References to elevated temperature mean temperature above ambient. For cooking purposes this is typically a temperature above about 70° C. for slow cooking or higher for conventional cooking.

We further describe a member for use in a heat transfer enclosure, the member being of thermally conductive material and comprising a contact surface for contacting an article located in the enclosure and projections extending generally away from said surface.

The member may be incorporated in a heat transfer enclosure on initial construction of the enclosure or as a retro-fit.

Preferred and optional features of this aspect are as discussed above.

We further describe a method of reducing or increasing the temperature of an article in a heat transfer enclosure, the article being in contact with the contact surface of a member of thermally conductive material that includes projections extending generally away from the contact surface, comprising contacting the projections with a heat exchange fluid at a lower temperature than the article for cooling, or at a higher temperature than the article for heating.

The heat exchange fluid is preferably conveyed past the projections, e.g. by use of a fan.

Preferred and optional features of this aspect are as discussed above.

We further describe use of a member of thermally conductive material having a contact surface for contacting articles and projections extending away from the contact surface to increase the effective surface area for heat transfer of as article in contact with the contact surface when the member and article are located in a heat transfer enclosure with a heat exchange fluid in contact with the projections.

The heat exchange fluid is at a lower or higher temperature than the article, and is preferably conveyed past the projections, e.g. by use of a fan.

Preferred and optional features of this aspect are as discussed above.

Embodiments of the present invention enables improvements in heat transfer on cooling or heating that can bring benefits either in enabling faster processing and faster throughput of articles and/or in enabling energy savings by use of a smaller temperature differential between the temperature of the article and the heat exchange fluid, leading to cost savings. It has been calculated that energy savings in excess of 30% can be achieved by use of embodiments of the present invention.

We note that preferred embodiments regarding the heat transfer enclosure and the member(s) which relate to processing or storing articles under conditions of reduced temperature, and in which the article contacts the contact surface of the member with an upper surface of the article, are equally applicable to embodiments, in which:

-   -   articles may be processed or stored under conditions of elevated         temperatures and in which the article(s) contact(s) the contact         surface of the member(s) with an upper surface of the         article(s), or     -   articles may be processed or stored under conditions of reduced         temperatures and in which the article(s) contact(s) the contact         surface of the member(s) with an underside of the article(s); or     -   articles may be processed or stored under conditions of elevated         temperatures and in which the article(s) contact(s) the contact         surface of the member(s) with an underside of the article(s).

The invention will be further described, by way of illustration with reference to the accompanying drawings, in which:

FIG. 1 is a schematic end view of part of a member in accordance with embodiments of the invention supporting articles in the form of rectangular containers, with FIG. 1A being an enlarged scale fragment of region C illustrating heat flow;

FIG. 2 is a schematic end view of a member as shown in FIG. 1 in a heat transfer enclosure supporting articles in the form of rectangular containers;

FIG. 2A is a schematic perspective view of the arrangement of FIG. 1;

FIG. 3 is a schematic end view of a member and containers as shows in FIG. 2, with a further member in inverted condition located on the containers;

FIG. 3A is a schematic perspective view of the arrangement of FIG. 3;

FIG. 4 is a schematic end view of a member in accordance with embodiments of the invention in the form of a spacer located between layers of containers;

FIG. 4A is a schematic perspective view of the arrangement of FIG. 4;

FIG. 5 is a schematic end view of a further spacer in accordance with embodiments of the invention;

FIG. 6 is a schematic end view of a further spacer in accordance with embodiments of the invention;

FIG. 7 is a schematic graph of temperature versus time;

FIG. 8 is a schematic perspective view of a depressor arrangement in accordance with embodiments of the invention;

FIG. 9 is a schematic cut-out perspective view of an enclosure with a conveying means in accordance with embodiments of the invention;

FIG. 10 is a schematic perspective view of an arrangement in accordance with embodiments of the invention; and

FIG. 11 is a schematic end view of part of a member in accordance with embodiments of the invention supporting an article in the form of a rectangular container, with FIG. 11A being a schematic perspective view of the member of FIG. 11.

DETAILED DESCRIPTION OF THE DRAWINGS

The drawings are highly schematic, and not to scale, to illustrate representative members in accordance with embodiments of the invention.

The member 10 shown in FIGS. 1, 2 and 2A comprises a planar member 12 having an upper face 14 constituting a contact surface with an array of parallel, spaced apart elongate planar ribs or fins 16 constituting projections extending at 90° from the opposed face 18 of the member. The member is made of metal, e.g. aluminium. The fins may be integral with, or secured to, face 18. In a typical embodiment, the fins have a fin length (extending away from face 18) of 25 mm, a fin width of 0.3 mm and spacing between the fins of 2 to 8 mm.

The member 10 is for use in a heat transfer enclosure represented at 30 in FIG. 2, such as a freezer or chiller, with the member being shown secured in position within the enclosure by mountings 32, and with articles in the form of rectangular boxes 34 containing goods such as food products or foodstuffs to be chilled or frozen. In practice, a typical chiller or freezer enclosure would contain a plurality of members 10, which need not be fixed in position but which could be mechanically movable within the enclosure in use thereof in known manner, as in an automated carton freezer.

The member 10 is designed to be able to support the load of the articles with which it is intended for use.

In use of the enclosure, a heat exchange fluid, typically chilled air, is brought into contact with the fins 16, typically being caused to flow past the fins along the length thereof, in a direction perpendicular to the plane of the paper of the figures, e.g. under the action of a fan.

The fins 16 can be considered effectively to increase the surface area of the boxes 34 and so to enhance heat exchange across the member 12 and so promote cooling of the boxes 34, as discussed shove. The arrows of FIG. 1A illustrate this heat flow.

FIGS. 3 and 3A illustrates a further similar member 10′ in position on top of the boxes 34, with heat exchange fluid also being caused to flow past the fins of member 10′ along the length thereof in use.

FIGS. 4 and 4A illustrate an alternative member 40 in the form of a spacer having parallel planar upper and lower plates 42, 44 connected by an array of parallel, spaced apart planar ribs or fins 46 extending perpendicularly to the plates. The spacer member 40 is located between two layers of boxes 34. The spacer member 40 is made of aluminium and functions in the same manner as members 10 and 10′, with heat exchange fluid flowing along the length of the fins 46 in use.

Optional corner or edge supports (not shown) may be provided extending between the plates to provide additional structural rigidity if required.

FIGS. 5 and 5A illustrates an alternative spacer member 50 formed from a sheet of metal, e.g. aluminium, deformed to produce a zig zag arrangement defining upper and lower planar contact surfaces 52, 54.

FIG. 6 illustrates an alternative aluminium space member 60 having parallel planar upper and lower plates 62, 64 the outer faces of which constitute contact surfaces connected by a regular array of columns 66 extending at right angles to the plates, the columns extending through and being connected to an array of spaced apart apertured plates 68 oriented to lie parallel to the plates 62, 64.

FIG. 7 is a schematic graph of temperature versus time showing changes in temperature over a 24 hour time period of an article to be frozen placed in a freezer enclosure on a conventional shelf and on a shelf in accordance with embodiments of the invention, with the upper line showing the profile for charges in the article core temperature on a conventional shelf and the line below showing the profile for a similar article on a shelf in accordance with embodiments of the invention. The two lower lines show profiles for changes in the temperature of ambient air (heat exchange fluid) in the enclosure, with the upper of these lines showing results using a shelf in accordance with embodiments of the invention and the lower line showing results for a conventional shelf. The ambient air temperature is higher with the shelf according to embodiments of the invention because more heat is extracted from the article, with higher efficiency. The article cools more quickly on the shelf according to embodiments of the invention compared with a conventional shelf (in both cases going through a relatively level temperature stage during the latent phase change state).

FIG. 8 is schematic perspective view of an arrangement 800. The arrangement has, in this example, a member 804 having projections extending generally away from the contact surface onto which article 802 is placed. The depressor member 806 exerts in this example a downward force (indicated by the arrow 808) onto the article 802 to urge the article 802 and contact surface of the member 804 into engagement. In this example, the depressor member 806 has projections generally extending away from its contact surface with which it contacts the article 802. This allows for further increasing heat transfer between the article 802 and, for example a heat exchange fluid, such as, e.g. an unconfined intervening fluid.

FIG. 9 shows a schematic cut-out perspective view of an enclosure 900 with a conveying means 904. In this example, the conveying means is a fan 904 which conveys the heat exchange fluid (which in this example is an intervening fluid, for example air) through the heat transfer enclosure 900 past the projections of the members 804 and 806, as indicated by arrows 906. This may allow for advantageously removing, for example heat from the article 802 more efficiently, i.e. at a higher rate. In this example, the arrangement for cooling the article 802 is identical to the arrangement of FIG. 8.

FIG. 10 shows a schematic perspective view of an arrangement 1000 for cooling articles 1002 a, 1002 b, 1002 c and 1002 d. The arrangement 1000 combines members shown, for example in FIGS. 1, 4, 5, and in some examples FIG. 6. In some examples, article 1002 a may merely be used to function as a depressor to urge the articles 1002 b, 1002 c and 1002 d and contact surfaces of respective members into engagement (as indicated by the vertical arrow 808). An intervening fluid can flow through the projections of the members 1004 a, 1004 b and 1004 c, as indicated by arrows 1006. This embodiment may be combined with the conveying means shown in FIG. 9.

FIGS. 11 and 11A show a schematic end view and perspective view, respectively, of part of a member 1100 supporting an article 1102 in the form of a rectangular container. In this example, the projections 1104, which extend generally away from the contact surface of the member 1100 onto which article 1102 is placed, have a substantially L-shaped form. The projections are in some examples between approximately 0.25 and 0.35 mm thin, such that attaching the projections to a plate functioning as the contact surface onto which the article is placed may be difficult. Therefore, providing the projections with a substantially L-shaped form may advantageously allow for simplifying attaching the projections 1004 to the plate to form the member. This may further improve the stability of the member 1100.

In some examples, the projections 1104 are attached to each other, whereby a part of the L-shaped projection overlaps with a part of the neighbouring projection(s). A separate plate which may function as a contact surface for supporting an article may not be needed in this example.

The material of the projections 1104 may be chosen such that it is compatible with the material of a chip (or other device) onto which the member 1100 is placed. In some examples, the material of the projections 1104 and the chip is identical. The material may be, e.g. aluminium.

Further aspects of the invention are described in the following clauses: 

1. A heat transfer enclosure for receiving articles to be processed or stored under conditions of reduced or elevated temperature, comprising one or more members of thermally conductive material having a thermal conductivity of at least 10 Wm⁻¹K⁻¹, said one or more members having a contact surface for contacting articles located in the enclosure and including projections extending generally away from said surface; wherein in use heat is conducted between an article contacting said contact surface with an underside or an upper surface of said article and a heat exchange fluid in said heat transfer enclosure via an article—contact surface—projections—heat exchange fluid heat transfer path.
 2. The enclosure according to claim 1, further comprising means to convey said heat exchange fluid through said heat transfer enclosure past said projections.
 3. The enclosure according to claim 1, wherein the projections are in the form of a plurality of ribs, fins or columns extending transversely to said contact surface; wherein the projections comprise an array of a plurality of parallel, spaced ribs.
 4. (canceled)
 5. The enclosure according to claim 1, wherein the projections are integral with and made of the same material as said contact surface.
 6. The enclosure according to claim 1, wherein the contact surface is one of a planar surface or a substantially planar surface.
 7. The enclosure according to claim 1, wherein the one or more members comprise a horizontally extending planar contact surface in the form of a shelf or tray on which an article can be placed to contact the underside of the article.
 8. The enclosure according to claim 1, wherein the member is configured to be used with the contact surface in contact with the upper surface of the article.
 9. The enclosure according to claim 1, wherein the member comprises a generally vertically extending contact surface configured to contact the side of articles.
 10. The enclosure according to claim 1, wherein the member comprises a horizontal spacer having parallel, spaced apart horizontally extending contact surfaces, to be placed between articles stacked on top of each other, with projections extending between the contact surfaces.
 11. The enclosure according to claim 1, further comprising a depressor arrangement to urge the article and contact surface into engagement.
 12. The enclosure according to claim 1, wherein a first said member is inverted compared to an orientation of a second said member, wherein said second member is configured to engage with an article surface opposite to the surface of the article with which said first member engages, and wherein in use said first or second member applies a force to urge said article and said contact surfaces of said first and second members, respectively, into engagement.
 13. The enclosure according to claim 1, wherein the member is fixed in position in the enclosure.
 14. The enclosure according to claim 1, wherein the member is movable within the enclosure in use thereof.
 15. The enclosure according to claim 1, further comprising a blast freezer, tunnel freezer, belt freezer, spiral freezer or helix freezer for use in batch, semi-batch or continuous mode.
 16. A member for use in a heat transfer enclosure, the member being of thermally conductive material having a thermal conductivity of at least 10 Wm⁻¹K⁻¹ and comprising a contact surface for contacting an article located in the enclosure and projections extending generally away from said surface; wherein (i) the member is configured to be used with the contact surface in contact with an upper or lower surface of the article; or wherein (ii) the member comprises a horizontal spacer having parallel, spaced apart horizontally extending contact surfaces, to be placed in an interleaving configuration between articles stacked on top of each other, with projections extending between the contact surfaces.
 17. (canceled)
 18. A method of reducing or increasing the temperature of an article in a heat transfer enclosure, the article being in contact with a contact surface of a member of thermally conductive material having a thermal conductivity of at least 10 Wm⁻¹K⁻¹ that includes projections extending generally away from the contact surface, comprising contacting the projections with a heat exchange fluid at a lower temperature than the article for cooling or at a higher temperature than the article for heating, such that heat is conducted between said article contacting said contact surface with an underside or upper surface of said article and said heat exchange fluid in said heat transfer enclosure via an article—contact surface—projections—heat exchange fluid heat transfer path.
 19. The method according to claim 18, wherein the article is in contact with a member configured for use in a heat transfer enclosure, the member being of thermally conductive material having a thermal conductivity of at least 10 Wm⁻¹K⁻¹ and comprising a contact surface for contacting an article located in the enclosure and projections extending generally away from said surface; and wherein the member is configured to be used with the contact surface in contact with an upper or lower surface of the article; or wherein the member comprises a horizontal spacer having parallel, spaced apart horizontally extending contact surfaces, to be placed in an interleaving configuration between articles stacked on top of each other, with projections extending between the contact surfaces.
 20. The method according to claim 18, wherein the heat exchange fluid is conveyed past the projections.
 21. The method according to claim 18, wherein the article and contact surface are urged into engagement with each other.
 22. The method according to claim 18, wherein the member is fixed in position in the enclosure or wherein the member is moved within the enclosure.
 23. (canceled)
 24. (canceled)
 25. (canceled)
 26. (canceled)
 27. (canceled)
 28. (canceled)
 29. (canceled)
 30. (canceled)
 31. (canceled)
 32. (canceled) 